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Welding from a Listeroid/ST generator rig

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38AC's balancing method in brief:

Take the flywheels off, make some sort of jig to suspend a length of 2" axle or smaller axle with 2" OD bearings in the flywheel.  I used wood, with some scrap angle iron for the load carrying edge for a 12" long piece of 2" rod. I leveled the angle iron pieces with paper and cardboard shims. The angles were screwed to the wood, one edge up.  38AC has a much nicer, welded steel jig- I don't recall details. 

 Set the wheel up on your jig and then add weight at 3 or 9 o'clock as needed to get the counterweight centered exactly at the bottom.  38AC had details on measuring and marking from the gib key slot to insure you know exactly where on the flywheel the top should be, which I've forgotten. You will realize why you need to do this when you see one or more of your flywheels resting way off angle from the key slot.  Measure the counterweight with a string and can weights suspended on the surface of the flywheel opposite the counterweight (63 and 9 o'clock).  Do the 2nd wheel, then add weight to the counterweight area rim of the lighter so it matches the heavier.  Now you have matching flywheels with a known counterbalance that is opposite the gib key.  My neighbor's DES 8/1 had about 43 oz of counterbalance weight, and we had to add about 8oz more (evenly split).

This removes all the "art" from the subsequent dynamic balancing.  Now you just add weight to a hopper until it stops jumping up and down and the head starts moving fore and aft ever so slightly.  Weight should be added equally to both wheels at the counterbalance or opposite (to subtract). 2 oz total increments is fine, double that if it's bad.

38AC mentioned that for fine tuning, a newly rebuilt engine will need a bit of running to loosen up a bit.
Note that for the 8/1 or SOM flywheels, the "counter weight" is by design and a lightening hole.

My memory is poor so I hope maybe 38AC will correct me!

Hi Bruce

Don't idolatre Butch, He's just an old guy wom thinks know some stuff.

But a WIS (means well informed source) told me this kind of fly balance by eye ball were passed to him by his grandson (belive me), and his grandkid said this will only will work just in one axis (say X), but you can have an inbalance in Y axis (dont ask me what is it, because I only got elementary school), but for low rpm it will work.

Well, so far some of our members said it works, so maybe it will work also with you.

Stay safe.
VP  ;D ;D ;D

PS: by the way Bruce, how do you call that fly?

This is a very simple form of doing a static balance and is a good start to getting it better than not balanced at all.
With what is called X,Y & Z axis these are terminology used in the machine shops for milling and machining.
These are;
Forward and Back
Left and Right
Up and Down
So I'm not sure how any other axis can come into play here other than the rotational direction on the vertical plane. It should not move left or right nor up and down.
So doing this simple test and correction using stick on wheel weights is the safest way to go because drilling out excess metal is a final one way journey for balancing and only recommended to be done by experts in balancing engines etc.

It was unfortunate that all my pictures were lost when the photo host shut down this the reason for the vanishing posts here.  No pics equals rest of post worthless. That being said an enterprizing individual happened to save all of my rants so there is hope at some point they will be available with pictures.
Balancing and engine the best and easy way first requires you to get the counterweight in the correct position with respect to the keyway. This is something that is messed up often in India. It is very important step and something you cannot pass by if you want the engine to run as smooth as it can be. To do this requires that you get the engine exactly at top dead center. Then place vertical marks on the flywheels. After that you place the flywheels on a balancing stand as Bruce suggested your marks that you placed previously must be vertical when the flywheel is allowed to freely rotate with the heavy spot down. The Next step is to match the offset weight in the flywheels. The easiest way to do that is to add weight to the flywheel with the least amount of offset weight. To check offset weight requires that the lines you mark on a flywheel be held horizontal by temporary weights attached to the light side. once you have the weight in the correct position and respect to the key way and equally weighted both flywheels you reattach them to the engine and adjust the offset weight to smooth out the operation. If the engine has too much offset weight it will be a scooter while running it will tend to walk across the floor. If the engine has too little offset weight it will be a hopper, up and down. Realize that you are attempting to balance a up and down motion which is the weight of the piston and half of the connecting rod via a circular motion with offset weight in the flywheels. None of these engines well set perfectly still but they can be made very good if you take all the steps. My first attempt at balancing was via the chalk method and attaching weight and I was not successful at it either.

 The link provided here is of a metro 61 that I balanced with my method.

Hi Bruce

Saw? the Master has spoken!

Nice, very nice Butch. And after all, that thing of X, Y  and Z axis was explained for all understand!



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